Various machines have been used for manufacturing plastic bags from folded plastic material so as to accomplish side welds spaced apart, and in the operation of such machines it has been necessary to cause the mechanism to separate a side welded area of a heat sealed bag from the oncoming folded plastic material so as to deliver the sealed bag and to separate it from the heat sealing roller during continuous or intermittent feed of the plastic through such machines. Some of the prior art machines drive the plastic intermittently and use various means for separating the heat-sealed bag and the oncoming plastic from the heat seal roller while the plastic is fed from a roll of plastic toward the heat sealing mechanism of such machines. Due to the various intermittent operations of prior art machines as well as the starting and stopping of various heat sealing and separating mechanisms, such prior art machines have been unduly limited in rate of production so that the number of bags per minute that can be produced has been the principal problem of operation.